Lubricator for earth-boring drills



May 1, 1923.

. 1,453,875 H. R. HUGHES IJUBRICATOR FOR EARTH BORING DRILLS Original Filed June 8 1920' WIT E & HR. HUGHES, INVENTOR.

FIG.1

I H is ATTORNEY.

especial appl Patented May 1 1923.

- UNITED STATES 1,453, 15 rarer orrlcs.

nowann a. HUGHES, or Los Antennas, CALIFORNIA.

LUBRICATOR FOB EARTH-BORING DRILLS.

Original application filed June 8, 1920,

To all whom it may concern: 1

Be it known that I, HOWARD R. HUGHES, a citizen of the United States, residing at Los Angeles, Los Angeles County, California, have invented a certain new and useful Imrovement in Lubricators for Earth-Boring Drills, of which the following is a full, clear, and exact description, such as will enable others skilled in the art to which it'appertains to make and use the same.

M invention relates to an improvement in lubricators for earth boring drills, and has ication to rotary boring drills to be used in deep well drilling.

In drillin for oil, water, gas, sulphur, etc., especialFy in hard formations, it is common to use roller boring drills having rolling cutters on the lower end thereof, these cutters being adapted to roll on the bottom of the hole, by the rotation of the drill stem to which the disintegrate the material. The disintegrated matter is washed away from the cutters and carried in suspension to the surface by means of the flushing fluid pumped downwardly through the hollow drill stem and through channels in the bit to the rotary cutters. In lubricating the rolling cutters it is customary to attach to the head of the bit a lubricating chamber in which the lubricant is placed and to force the lubricant from this chamber to the bearings by using the pressure of the flushing fluid against the piston resting on the upper surface of the lubricant. It will be obvious that the lubricant in the chamber operates under the pressureof a head of water standing in the well and that the pressure of the flushing fluid within the drill stem must be greater than the head of water outside the drill stem. This excess of pressure on the piston is brought about by the pump pressure acting on the flushing fluid. cess of pressure within the drill stem is due to the damming up of the flushing fluid above the head of the bit due to the small channels conducting thefluid through the head of the bit to the cutters. In this system it is obvious that the force acting on the lubricant is dependent entirely upon the pumps which force the flushing fluid downwardly through the drill stem.

An object of my invention is to provide a lubricator for deep well drills of this character which will operate independently of drill is attached, and thereby The malntenance of the ex-' Serial No. 387,299. Divided and this application filed May 28, 1921. Serial No. 473,225.

the flushing fluid within the drill stem and the well. 7

Another object is to provide a lubricator of this character which will operate with a constant pressure at all times.

These and other objects and advantages will most clearly appear from the description which follows.

Referring to the drawing herewith in which like numerals of reference are applied to like parts throughout the several views. Fig. 1 is a central longitudinal section through a drill stem and drill in which my improved lubricator is used. Fig. 2 is a transverse section on line 2-2 of Fig. 1. Fig. 3 is a broken detail showing the use of a spring in place of the weight shown in Fig. 1 in operating the piston.

This application is a pending application No. 8, 1920. In this embodiment of the broad invention set forth in said prior application I have shown the lubricator in substantially the same form disclosed in my previous Patent No. 930,759, granted August 10, 1909. The roller bit 1 to which the lubricator is attached is the so-called Hughes cone bit'because of the conical shape of the cutters 2 on the forward end thereof. This bit is connected by means of a drill collar 3 to a length of pipe 4. connected by means of a collar 5 to a special coupling 6 through which it is attached to the drill stem 7 The bit 1 has an upwardly extending nipple 8 to which the lubricator barrel 9 is connected by means of a valved coupling 10. The upper end of the barrel 9 is connecte by means of a swaged coupling 11 to a smaller tube 12 which extends upwar v through the said coupling 6 within the drill stem 7 The coupling 6 comprises a casting which serves to connect the drill stem with the pipe 1 and also partiall closes the passage downwardly through t e drill stem. Longitudinal passageways 13, shown best in Fig. 2, allow the flushing water to pass downwardly to-the drill. In the upper face of the coupling 6 there is a central countersunk recess 14 providing a threaded attachment for an upwardly extending cap or chamber 15, into which the tube 12 is adapted to extend. Into the lower end of the recess 14 laterally extending passageways 16 find an entrance.

In the lower face of the coupling 6 is a equivalents and either stuffing box which maintains a close fit between the tube 12 and the coupling so as to prevent flushing fluid from leaki g about the outer surface of the tube.

The lubricating barrel 9 is adapted to contain a rather thick heavy lubricant which is pressed upon by the piston 17, thereby tending to force the lubricant downwardly through a perforated disc or strainer 18 and the valve controlled passage 19 to the bit. In the head of the bit the ducts 20 allow a passage of the lubricant downwardly to the bearings of the cutters 2. The piston 17 is acted upon by a weight 21 which is shown as incorporated with the piston for convenience of manufacture, said weight having leather cups or packing at the upper and lower ends thereof.

A spring may be substituted for the weight, as shown in Fig. 3, it being well known that aweight and spring are common will act under the conditions of drilling to exert a downward pressure upon the piston.

In the operation of my device the flushing water is pumped downwardly through the drill stem, the passages 13 in the coupling, and the channels 22 in the head of the bit to the cutters. No opportunity is allowed for the flushing water to exert a pressure upon the piston in the lubricant chamber. The flushing fluid without the drill stem may find an entrance through the channel 16 to the chamber 15, and from thence downwardly through the tube 12 to the lubricant chamber. Thus it will be seen that the pressure upon the piston is due to the head of water standing in the hole and not to pump pressure. This pressure is counterbalanced by the backward pressure of flushing fluid exerted against the lubricant ducts leading to the bearings and hence equalizes the pressure on the lubricant. The result is a pressure upon the piston due solely to the force of the weight 21 or the spring 21'. This pressure may be regulated within a fair degree of accuracy to exert the exact amount of pressure found best suited to feed the lubricant to the bearings as desired.

The particular construction of this device whereby there is a rotatable yet fluid tight connection between the lubricant chamber and the chamber 15 has been that the device may be most easily assembled. A careful inspection of the construction of the device will show the manner in which the device is assembled. The lubricator attachment is connected to the bit with the tube 12 upstanding above the upper end of the pipe 4. The casting or coupling 6 is then connected by means of the collar 5 to the pipe 4. The rotation of the coupling neces sary for this connection is accomodated by the stufing box in the lower face of the below said inlet and developed so 1 coupling. By this means the rotation of the member 6 relative to the tube 1.2 is allowed without at the same allowing leakage about the tube.

By this form of construction I have provided a lubricator which is unaffected by the action of the flushing water to the extent that the pressure of the same is equalized {relative to the lubricant. The only pressure then acting to drive the lubricant is that of the weight or the spring bearing upon the piston.

Having thus described my invention, what I claim as new and desire to protect by Letters Patent, is:

1. In a rotary earth-borin drill, a. drill head having rotary cutters t ereon, a drill stem operatively engaged with the up er end of said head, a lubricator barrel attac ed to said head inside said drill stem, and connected with the bearings of said cutters, a

piston on the lubricant therein, means to ap proximately equalize the fluid pressure in said lubricator during the operation of the drill, and additional means to force said piston downwardly in the barrel.

2. In a rotary earth-boring drill, a drill head having rotary cutters thereon, a drill stem operatively engaged with said head, a

lubricator barrel attached to said head inside said drill stem, connecting ducts between said lubricator and the bearings of said cutters, and a piston on the lubricant in said barrel, the fluid pressure in said barrel being approximately balanced, and the piston being weighted to force the lubricant downwardly to the bearings of said cutters.

3. In a rotary boring drill, a drill stern, a drill bit attached thereto, a, lubricant chamher on said bit and spaced within said drill stem, said drill stem providing a passage outside said lubricant chamber to said bit for flushing fluid, an said drill stem to said chamber, a plunger means to force said plun er downwardly upon said lubricant for t e purpose specified.

4. In a rotary boring drill, a drill stem, a drilling tool attached thereto comprising a head having cutters rotatable on bearings thereon, said head having channels therein to conduct flushing fluid to said cutters, a ubricator on said tool spaced within said drill stem, 'means to prevent entrance of said flushing fluid from within said drill stem to said lubricator, said drill stem having passages arranged to allow entrance of flui to said lubricator from without the drill stem to equalize the fluid pressure within said lubricator and separate means to force lubricant from said lubricator to said bearings.

5. In a rotary boring device,

a drill stem, a drilling tool attached thereto comprising a inlet from without head having rotary cutters thereon, a central lubricator secured to said head within said drill stem, a closure for the upper end of said lubricator having-a tube thereon connecting with the outside of said drill stem to allow entrance to said lubricator of flushing fluid, a plunger in said lubricator, and means to force said plunger downwardly upon the lubricant in said lubricator.

6. In a rotary boring device, a drill stem, a drilling tool attached thereto comprising a head having rotary cutters thereon, a lubricator attachment on said head comprising a tubular chamber, apiston above the lubricant therein, a fluid passage from without said drill stem to said chamber, and means connected with said piston to force it downwardly in said chamber.

7. In an earth borino drill, the combination of a drill stem, an a drill head having rotary cutters thereon with a lubricator attachment comprising a central container secured to said head inside said drill stem, a piston in said container, a passage connect- 25 ing the space above said piston with the a drill head thereon, cutters on said head, a t

lubricator barrel on said head, a piston in said barrel, a tube on the upper end of said barrel, a chamber above said lubricator barrel having connections with the space out side said drill stem and with said tube, and means to force said piston downwardly with uniform pressure.

9. In arotary earth boring drill, a drill head having rotary cutters thereon, a drill stem, a coupling thereon artly closing the passage through said drilF stem, a chamber formed thereon, having passages connecting with the outside of said drill stem, a lubricator barrel connected with said drill head, and having its upper end also connected with said chamber and a weighted piston in said barrel.

In testimony whereof, I hereunto aflix my signature this 19th day of May, A. D. 1921.

HOWARD R. HUGHES. 

